Don’t It Make My Brown Fat White

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What causes “good” brown fat to turn into “bad” white fat? Boston University researchers say the unfortunate transformation happen when you eat too many high calorie foods. They found that this habit not only leads to an increase in white fat cells (the type prominent in obesity) but that it also makes brown fat cells (the type that generate heat and burn energy) “whiten”. The results were published in April 2014 in the Journal of Clinical Investigation.

A release from the university explains that the team demonstrated that “over-nutrition” leads to a cellular signaling dysfunction that causes brown fat cells to lose neighboring blood vessels, which deprives the cells of oxygen. In turn, this causes the brown fat cells to lose their mitochondria, which leads to their inability to burn fatty acids and produce heat. This collapse can have far-reaching effects on the development of metabolic conditions such as diabetes or cardiovascular disease.

The release quotes senior author Kenneth Walsh, PhD as saying, “If we go back to when humans were hunter-gatherers, days could pass between when they could eat, so it was a survival advantage to be able to store excess energy in white fat cells. What served us so well as primitive organisms is now hurting us because we have a continuous food supply and are accumulating too many white fat cells.”

The study findings highlight the important relationship between fat tissue and the cardiovascular system and indicate that the cardiovascular risk factors, such as hypertension and high cholesterol that contribute to blood vessel damage, could also lead to the dysfunction of brown fat cells.

“In addition to the expansion of white fat cells, our study shows that overeating causes brown fat cells to get locked into a death spiral, leading to their ultimate dysfunction,” Walsh said. “More research needs to focus on whether stopping these activities from happening in brown fat cells could help combat obesity.”